So it analysis relies on a variety of reputation states that are within almost every other Triassic archosauromorph lineages (age
six.dos.1 Diagnosing the Genus Revueltosaurus
The newest holotypes from R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), therefore the has just attributed variety “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert ainsi que al., 2012 ) per comprise one remote enamel that has been the foundation getting their particular diagnosis. Most recently, Heckert ainsi que al. ( 2012 ) diagnosed the fresh new genus Revueltosaurus (spanning Roentgen. callenderi, Roentgen. hunti, and you will R. olseni) with the after the mixture of reputation states: proportions (tooth crowns up to eight to help you fifteen-mm tall); several brief denticles (more than eight each carina) that are counterbalance (sub-perpendicular) towards the enamel margin; denticles proportionately short and frequently used toward enamel of the accurate occlusion; diminished a genuine cingulum; premaxillary enamel crowns which can be as much as doubly extreme since the maxillary/dentary tooth crowns and you will weakly recurved; and you will maxillary/dentary enamel crowns phyllodont (leaf-shaped). g., Ezcurra, 2016 ). Such as, the blend of sized tooth, what amount of this new denticles, while the direction of the denticles overlap with other distantly associated taxa (elizabeth.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn et al., 2010 ). The type “denticles proportionately brief and often worn towards the enamel by the particular occlusion” lacks precision with respect to what exactly is experienced “quick,” and wear development is difficult to help you rule out in other taxa and relies on a certain chronilogical age of enamel within the substitute for cycle (we.elizabeth., younger white teeth would not be diagnosable because there would not be worn). In addition, the absence of apomorphic character states (age.g., absence of cingulum) should not be included in a diagnosis, because they’re symplesiomorphies. At exactly the same time, the new task away from enamel status based on just one enamel (e.g., premaxillary enamel crowns is actually around doubly extreme since maxillary/dentary enamel crowns and you may weakly recurved; maxillary/dentary tooth crowns leaf designed) can’t be calculated about amazing type of matter, as well as with more white teeth throughout the same locality, just craniodental thing that have pearly whites also have the latest association away from tooth figure and enamel status. Hence, the newest proposed tooth updates of one’s holotype pearly whites out of K. hunti and you will P. olseni is assumed predicated on an enthusiastic inferred personal relationship with R. callenderi, which is understood from craniodental issue that have white teeth (find more than). In conclusion, new genus Revueltosaurus sensu lato can’t be sufficiently and you may sustainably recognized in accordance with the style of information of Roentgen. callenderi, K. hunti, and you can P. olseni and we also therefore restriction this new genus to at least one species, R. callenderi. Therefore, i propose that “R”. hunti take care of the personal junior word Krzyzanowskisaurus hunti once the erected from the Heckert ( 2005 ) and you will “R”. olseni keep up with the personal elder word Pekinosaurus olseni. We next warning the latest project of every present separated enamel taxa to Revueltosaurus.
We would keep in mind that down the road, with increased complete topic, Roentgen. callenderi, Krzyzanowskisaurus hunti, and you may Pekinosaurus olseni may chatib promo kodu represent an excellent monophyletic genus Revueltosaurus, but an assignment of all the around three kinds to a single genus isn’t already you can because makes an a priori assumption regarding dating (discover below) which is synchronous into original dispute your Revueltosaurus teeth was in fact assignable in order to Ornithischia first off. This might features unwelcome cascading effects to the after that macroevolutionary knowledge (age.g., biogeography and you will paleocology). Instead, it is also quite possible why these taxa may start aside to-be distantly relevant.
six.2.dos What is actually Krzyzanowskisaurus hunti?
Heckert ( 2002 ) revealed “Revueltosaurus” hunti, after assigned to new genus Krzyzanowskisaurus (Heckert, 2005 ), considering separated white teeth from the Los Esteros Person in brand new Santa Rosa Formation (Dockum Category) from inside the central New Mexico and Blue Mesa Member of the new Chinle Formation in east Arizona (particular locality away from An effective. geoffreyi-select ), and also already been acknowledged about all the way down Chinle Development in the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti teeth is actually famous from R. callenderi white teeth by the exposure out of an effective ridge (“cingulum”) on the bottom of tooth crown, and this links into the carinae and that’s tend to denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, et al., 2007 ; Rates 14a, b). Originally, Krzyzanowskisaurus is actually called given the different morphology of the white teeth between the two versions plus the conflict that the Krzyzanowskisaurus teeth still was in fact assignable to a keen ornithischian in place of good pseudosuchian (Heckert, 2005 ). Irmis, Parker, mais aussi al. ( 2007 ) disagreed with the assignment away from Krzyzanowskisaurus hunti towards Ornithischia oriented toward comparable objections outlining the issues off delegating remote white teeth so you’re able to ornithischians once the displayed before and the framework you to definitely Heckert ( 2002 , 2005 ) identified as an effective “cingulum” was not homologous with similar structures during the ornithischian dinosaurs. Additionally, Irmis, Parker, ainsi que al. ( 2007 ) and indexed one to good Revueltosaurus-instance squamosal, quadrate, and osteoderms were also bought at an equivalent Arizona locality since the Krzyzanowskisaurus hunti white teeth, just as got occurred from the form of locality getting R. callenderi (See mais aussi al., 2005 ).
